Fuse plug



Ill

Patented Dec. 2, 19 24,

un 'rsn STATES- ERIC G, LARSON, OF SALT LAKE CITY, UTAH.

FUSE PLUG.

Application filed January 26, 1923. SeriaINo. 614,983.

T 0 alZ whom it may concern: 1

Be it known that I, ERIC G. LARsoN, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State "of Utah, have invented certain new anduseful Improvements in Fuse Plugs,.of which the following is a specification.

My invention relates to fuse plugs, and has for its object to provide a fuse plug which may be renewed, and used after .repeated fuses have been burned out by the electric current and without taking the fuse plug out of the line socket.

A further object is to provide a fuse plug so constructed and arranged that when one line of the electric circuit has been cut by the burning out of the fuse the defective fuse plug may be easily andconveniently determined by sight and the defect instantly remedied.

A still further object is to provide a fuse plug with yielding ball and socket and slid ing contacts and which willform a better electric circuit than has been heretofore practiced. i

These object I accomplish with the device illustrated in the accompanying drawings in which similar letters and numerals of reference indicate like parts throughout the several views and as described in the specification forming a part of this application and pointed out in the appended claims.

In the drawings in which I have .shown a substantial embodiment of my invention Figure 1 is an end elevation of my device. Figure 2 is a side elevation of the device. Figure 3 is a diametrical section. Figure 4 is a plan and edge view of the fuse. Figure 5 is a plan and diametrical'sectionof the insulator.

The present invention consists of the commonly used porcelain plug A externally threaded at one end portion as at B and on which .is carried thethreaded contact sleeve nut C. The said porcelain-plug A is hollowe out around its axis and perforated through its side with an elongated slot D adjacent the end of said contact nut C. A metal spring contact post E is fastened within the hollowed out interior of said porcelain plug A by bending the inner end portion of said contact post, shown at 2,into sleeve form and pressing it or striking it to-form an eyelet I which grips the outer and inner faces of said porcelain. The free end por tion of said contact post E is given a spherlcal form for a contact member, as at 3, and

with axial position as to said porcelain plug A, and with the tension of the spring tending to move said member 3 axially outwards Another spring contact post F is secured-to said sleeve C and passes through the elon-' gated slot D and extends to near the base of said porcelain plug A, Where it is bent at right angles to its general plane and at an incline as to the base of said plug A to form an inclined contact member 4, and spaced from said spherical contact member 3. An outwardly extended flange portion 5 .of said porcelain plug A is serrated to aid in screwing my device into or out of the line socket. A metal cup-shaped cap G having a sight opening in its bottom, as at 6,.is detachably fastened on the base endof said porcelain plug A and portions of its perimeter are to be struck radially inward, as at 7, to engage in contiguous notches which have been formed in the perimeter of an insulator I, which is the means I use to retain the cap G and its connections in adjustable relation to the porcelain plug A and its connections. The said sight opening 6 is to be covered on its inner face by a transparent member 8 in order that the interior of my device may be easily examined byzobservation. A perforated insulator I is secured to and carried within said cap G contiguous said transparent member 8 and is to be partiallyrotated on its axis by moving said cap G as desired to adjust the fuses. The inner face of said insulator I is recessed similar to a spoked wheel, with a semi-spherical centrally located recess 10 and with radially disposed slots 11 extending therefrom over the perforations 9 through said insulator and deepened at their outer ends. A wheelshaped fuse member H is carried in said recesses 10 and 11 and which fuse is made of thin fuse material, and has its central or axial portion struck in,semi-spherical shape, as at 12', to conform with the said recess 10- of said insulator I. The spoke portions 13 of said fuse member H are narrowed at 1 their medial portions, as at 14, in order that a weak or. easily melted portion may be formed contiguous the perforations 9 in said insulator I. The end of each of the said' spoke portions 13 of the fuse is bent at right angles to the plane of the fuse to engage in the deepened end of said recesse 11, in orde r that when a portion of said fuse is melted off it will not fall and come in contact with the other unused portions of the fuse. The said recesses 11 are made deeper than the thickness of the fuse material in order that all of the said recesses'll will not be filled with the spokes of the fuse, thereby allowing the face or portion 4 of the contact post F to engage in each of said recesses 11 as they are moved over or across the inclined end of said contact post F. If desired, the inclined end of said post F may be colored in order that the melting of one of the spoke fuses may be determined by sight.

The operation of my device is as follows My fuse plug is screwed into the line socket as an other fuse plu the serrations 5 aiding this operation. n electric circuit will be formed by the usual contact with the sleeve nut C and the contact post F when touching the outer end portion of any one of the spokes 13 of my fuse, and the sphericall -shaped contact member 3, which touc es the fuse at 12, and the eyelet 1 completing the circuit.

Should the particular spoke portion 13 of my plug be burned out or melted by short circuit or overload, the particular spoke will be burned or melted at its weak or narrowed point 18, which may be easily seen through the transparency-8, and then, by rotating the cap Gr toward the right, another spoke 13 will be brought in touch with the contact post F, which may be determined by sight or by a light or slight sounding noise made by the inclined end of said post when it slipsinto the recess 11 in which that spoke is carried. Other similar injuries to the fuse plug may be repaired by again turning the said cap G and bringing another one of the spokes 13 in touch with said post F. Preferably, I have six spokes in a use plug for common house lig ting car,- rying the ordinary light circuit.

1 thus provide an economical fuse plug having a fuse with radially disposed arms each insulated from the other, with a cap in which said fuse is carried and by which it is operated, with means for easily detecting which particular arm, and in which particular plug, any injury has occurred, thereby lengthening the lite and use of my plug.

Having thus described my invention and its use and operation, I desire to secure by Letters Patent and claim 1. A fuse plug comprising an externally threaded hollowed plug having a serrated flange portion thereon, and a slotted opening in its side opening to the interior; a threaded metal sleeve nut screwed on the threaded portion of said plug; a contact post attached to said sleeve nut and passed through said slotted opening in said plug having its free end at an incline as to the base of said plug; a spring contact post secured axially within said plug and having a spherically shaped end thereon; a cap member having a sight opening in its bottom detachably carried on and as a cover for said plug; a perforated insulator carried in said ca and movably therewith and having a whee shaped recess cut in its inher face; and a wheel-shaped fuse carried in the recess of said insulator having a semispherical recess axially therein to receive the spherical end portion of said spring contact post and with! the spoke portions narrowed.

2. A fuse lug comprising a porcelain plug with ho lowed interior; a sleeve nut carried on said plug; a contact post attached to said sleeve nut and extended to the interior of said plug; an axially disposed spring contact post secured in the bottomjof said plug; a spherically-shaped contact -point on said last mentioned contact post;

a cap member having a sight opening in its bottom carried on said plug; a perforated insulator carried within and by said cap member and having a wheel-shaped recess formed on its inner :face; and a wheelshaped fuse carried in said recess having a semi-spherical recess axially therein to receive said spherical contact point and whose spoke portions are narrowed adjacent the perforations of said insulator with the free ends of said spoke portions adapted to contact with the end portion of the first mentioned contact post.

In testimony whereof I have affixed my signature.

naic e. mason. 

